24 Trypanosomiasis, West Nile Virus, Schistosomiasis

Sleeping Sickness or Chagas Disease

What are the common names for Trypanosomiasis?

African: Trypanosoma brucei gambiense and brucei rhodesience
American: Trypanosoma cruzi

What are the causative agents of Trypanosomiasis?

Yes

Is Trypanosomiasis zoonotic?

Trypanosoma brucei gambiense

Humans are the primary reservoir, with ungulates and primates also able to host in what species of Trypanosoma?

Cattle

Which animal is the primary reservoir for Trypanosoma brucei rhodesience?

All mammals

What animals are susceptible to Trypanosoma cruzi?

T. cruzi

Which Trypanosoma species is found in the Americas?

Trypanosomiasis

Signs for this infection include intermittent fever, anemia, weight loss, lethargy, vomiting, diarrhea, swollen lymph nodes, serous atrophy of fat, with extensive petechiation of serosal membranes in fatal cases

1-4 weeks

What is the incubation period for Trypanosomiasis?

Can have rapid death or death with chronic, untreated cases

What is mortality like for Trypanosomiasis?

Trypanosomiasis

What infection can you diagnose with observation of stained blood smears and wet mounts to look for motile parasites?

Bites from Tsetse fly

What is the vector for the AFRICAN variant of Trypanosomiasis?

Ingestion of or Bites from Kissing (redvuiid) bug

What is the vector for the AMERICAN variant of Trypanosomiasis?

Fly control (spray, dipping). Pesticides

How can you control Trypanosomiasis?

YES

Is Trypanosomiasis reportable?

Trypanosomiasis

What is this?

West Nile Encephalitis or West Nile Virus

What does WNE/WNV stand for?

West Nile Virus

What is the leading cause of mosquito borne disease in the continental U.S.?

Flavivirus: Orthoflavivirus nilense

What is the causative agent of West Nile Virus?

Birds and alligators

What animals are the definitive host for West Nile Virus?

Horses and Humans mainly (though many other mammals are obviously included)

Though birds and alligators are the definitive West Nile Virus hosts, what other species can be infected?

Yes

Is West Nile Virus zoonotic?

West Nile Virus

This infection often presents mildly in horses, but can cause neurologic disease, lethargy, inappetence, ataxia, weakness, head/neck tremors, muscle fasciculations, opisthodomos, and convulsions/paddling

West Nile Virus

In humans, this infection presents with fever, headache, body ache, vomiting, neuroinvasive disease, encephalitis, and meningitis

Human: Morbidity: 20%, mortality 5%
Birds: normally nonpathogenic but higher mortality in American birds
Horses: Morbidity: 20%, mortality 30%

What is morbidity and mortality of West Nile Virus like in humans? What about birds and horses?

Low viral load

Why is virus detection of West Nile Virus unreliable in horses?

Bite of infected mosquito (Culex), vertical transmission (pregnancy, delivery, breast feeding)

How is West Nile Virus transmitted?

Dead End host

What types of hosts are horses and humans for West Nile Virus?

Supportive care or euthanization (horses)

How can you treat West Nile Virus?

YES

Is West Nile Virus reportable?

None for humans, vaccines for horses available

What type of vaccine is available for West Nile Virus?

Snail Fever

What is the common name for Schistosomiasis/Billharzia?

Schistosoma haematobium or japonicum or mansoni

What is the scientific name for Schistosomiasis?

Intestinal, urogenital, systemic, CNS

What different tracts can Schistosomiasis affect?

Schistosomiasis

This infection can present with a range of symptoms: abdominal pain and blood in stool, hematuria, fibrosis of bladder/ureter, infertility, eosinophilia, CNS lesions, scarring, calcification, and embolic egg granulomas

Morbidity: 75 million globally
Mortality: 12,000 deaths

How many people are affected with Schistosomiasis every year? How many die worldwide?

Fecal/urine examination for ova, serologic testing for antischistosomal antibodies

How can you diagnose Schistosomiasis?

Eggs excreted through urine, eggs hatch in freshwater and penetrate IH snail. Parasites reshed into water and penetrate DH mammal via skin contact

How is Schistosomiasis transmitted?

Praziquantel

What is the recommended treatment of choice for Schistosomiasis?

Avoid urine contact with freshwater sources

How can you avoid Schistosomiasis?

Schistosoma

This parasite lives primarily in urogenital venules and feed off RBCs, but can live in other mesenteric venules and release eggs into host intestines.